Guys, let me tell you from personal experience because of my steep drive way that is slanted left to right. If I don't replace the bolts, when I'm at the bottom of the drive way going up or down, the front suspension creaks. Problem always solved by replacing these bolts, therefore it's necessary to replace them. But I always do so when I'm finally done with any repairs that requires removing them. For example, I have new ones waiting till I'm done with all the oil leaks etc I'm dealing with.

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'05 E53 X5 4.4i, '97 E39 528, '07 E92 335i, '16 F86 X6M.